One type of vascular disease is occlusive vascular disease, which includes conditions sometimes referred to as chronic total occlusion (CTO). A typical CTO is a lesion located in a blood vessel of a patient that results from an accumulation of deposits, typically calcified fibrin, therein. Occlusive vascular disease can cause blockages in both coronary and peripheral blood vessels. A blockage in a coronary blood vessel is a very serious condition that can lead to angina or myocardial infarction.
Occlusive vascular disease is generally characterized by a hardened, calcified deposit substantially or completely blocking the flow of blood through a blood vessel. Traditionally, this type of disease has been treated by both bypass surgery and/or drug therapy. Recently, it has been discovered that occlusive vascular disease can also be treated by advancing a guidewire through or across the diseased location to create a passageway for interventional treatment, i.e. angioplasty. In such a procedure, the guidewire is used to puncture through the hard deposit in order to create a pathway for balloon catheter or stent delivery to the lesion site. Techniques in this regard can include what is known in the art as “dottering” by which the device is subjected to short alternating advancing and retrograde movement so the tip or the like that engages the lesion site imparts short thrusts to in a sense peck away at the diseased location.
Typically, a guidewire and a catheter are separate devices that are used in percutaneous transluminal coronary angioplasty (PTCA) procedures, with the guidewire performing essentially a guiding function for the PTCA catheter that effects the desired medical procedure. The present disclosure recognizes that combining a guidewire-type device with a PTCA catheter into an integral device can have important advantages.
Some of the challenges that have been encountered in using the guidewire technique for occlusive vascular disease treatment include difficulty in positioning the guidewire prior to and during the lesion crossing procedure and misalignment of the distal tip of the guidewire, which has the potential to lead to unintended perforation of the blood vessel.
Therefore, a need remains for a medical device that can be easily positioned prior to and during lesion crossing and/or treatment and also reduces the risk of perforating the blood vessel.